hibernate主要方法調用

Question

我對Hibernate很陌生，只想查詢最初的基礎知識。

我已經建立了我的Hibernate bean作爲這樣...

package com.behaviour.chapter1; 

import javax.persistence.Entity; 
import javax.persistence.Id; 

@Entity 
public class User { 

    private int userId; 
    private String firstName; 

    @Id 
    public int getUserId() { 
     return userId; 
    } 
    public void setUserId(int userId) { 
     this.userId = userId; 
    } 
    public String getFirstName() { 
     return firstName; 
    } 
    public void setFirstName(String firstName) { 
     this.firstName = firstName; 
    } 
} 

我有我的配置和hibernate.cfg.xml的數據庫連接。我的問題很簡單，我如何從一個主要方法實際調用它並在Hibernate3.6.6中使用它？我在線上學習了一個教程，但是它是用於Hibernate3.2的，它看起來有點不同。如果任何人都可以向我展示調用這個bean的一個非常簡單的主要方法，創建一個新用戶（這將在此表中創建一個用戶），這將不勝感激。同時 - 如果任何人有任何良好的Hibernate的教程鏈接，將是巨大的:)

感謝，

Answer 1

有這樣的幾個方面，它是設計的選擇，一個基本的方式來實現，這將是從hibernate.cfg.xml文件中創建會話工廠的問題。確保文件可以位於你的類路徑中。

而使用下面的類，創建然後用於打開一個會話工廠對象新的Session

public class HibernateUtil 
    { 
    private static final SessionFactory sessionFactory; 

    static 
    { 
     try 
     { 
     // Create the SessionFactory from hibernate.cfg.xml 
     sessionFactory = new Configuration().configure().buildSessionFactory(); 
     } 
     catch (Throwable ex) 
     { 
      // Make sure you log the exception, as it might be swallowed 
      System.err.println("Initial SessionFactory creation failed." + ex); 
      throw new ExceptionInInitializerError(ex); 
     } 
     } 

     public static SessionFactory getSessionFactory() 
     { 
     return sessionFactory; 
     } 
    } 

我們創建一個新用戶，請：

public class DaoFactory 
{ 
    public void create(Object obj)throws Exception 
    { 
    Session session = HibernateUtil.getSessionFactory().getCurrentSession(); 
    session.beginTransaction(); 
    session.save(obj); 
    session.getTransaction().commit(); 
    } 
} 

Main

public static void main(String[] args) 
{ 
    try 
    { 
    User user = new User(); 
    user.setFirstName("david99world"); 
    DaoFactory factory = new DaoFactory(); 
    factory.create(user); 
    } 
    catch(Exception ex) 
    { 
    ex.printStackTrace(System.out); 
    } 
} 

編輯

你hibernate.cfg.xml應該是這個樣子：

<?xml version='1.0' encoding='utf-8'?> 
<!DOCTYPE hibernate-configuration PUBLIC 
"-//Hibernate/Hibernate Configuration DTD 3.0//EN" 
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd"> 
<hibernate-configuration> 
<session-factory> 
<!-- Database connection settings --> 
<property name="connection.driver_class">com.mysql.jdbc.Driver</property> 
<property name="connection.url">jdbc:mysql://localhost:3306/test</property> 
<property name="connection.username">root</property> 
<property name="connection.password">root</property> 

<!-- JDBC connection pool (use the built-in) --> 
<property name="connection.pool_size">1</property> 

<!-- SQL dialect --> 
<property name="dialect">org.hibernate.dialect.MySQLDialect</property> 

<!-- Enable Hibernate's automatic session context management --> 
<property name="current_session_context_class">thread</property> 

<!-- Disable the second-level cache --> 
<property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property> 

<!-- Echo all executed SQL to stdout --> 
<property name="show_sql">true</property> 

<!-- Drop and re-create the database schema on startup --> 
<property name="hbm2ddl.auto">none</property> 

<mapping class="com.behaviour.chapter1.User"/> 

</session-factory> 
</hibernate-configuration> 

Answer 2

Hibernate的教程

Hibernate tutorial-1

Hibernate tutorial -2

Answer 3

你需要一個Session對象訪問持久性單元。這些對象由SessionFactory對象提供。

檢查the Hibernate reference guide。

Answer 4

我假設你已經設置了你的persistence.xml。如果是這樣，您可以使用以下Java代碼。你必須用你的JDBC設置數據和持久性單元替換「...」。

private static final String PERSISTENCE_UNIT = "..."; 

final Map<String, String> properties = new HashMap<String, String>(); 
properties.put("javax.persistence.jdbc.driver", "..."); 
properties.put("javax.persistence.jdbc.url", "..."); 
properties.put("javax.persistence.jdbc.user", "..."); 
properties.put("javax.persistence.jdbc.password", "..."); 

final EntityManagerFactory emf = Persistence.createEntityManagerFactory(PERSISTENCE_UNIT, properties); 
final EntityManager em = emf.createEntityManager(); 

User user = new User(); 
user.setUserID(0); 
user.setFirstName("David"); 

em.getTransaction().begin(); 
em.persist(user); 
em.getTransaction().commit(); 

HTH

樂